RegEx表达式将匹配特定格式的字符串(RegEx expression that will match string of a particular format)

我有一行ORDER BY DESC(?year) ，其中?year可以是任何后跟问号(?)名称，例如？名称，？地址等。我尝试了ORDER BY DESC$\?[az]+$将整个字符串捕获为ORDER BY DESC(?year)但不起作用。

lex文件：

%{ #include <cstdio> #include <iostream> #include "grammar.tab.h" %} %option case-insensitive %% [1-9][0-9]* { yylval.i = atoi(yytext); return INT_NUM; } "ORDER BY DESC$\?[a-z]+$" { yylval.s = strdup(yytext); return ORDER_BY_DESC; } "\n" { yylineno++; } \. { return DOT; } [ \t]+ { /* ignore white space */ } "#".* { /* ignore comments */ } [ \t\v\f\r]+ { } . { std::cerr << "Lexical Error!\n"; } %% int yywrap() { return 1; }

野牛档案：

%{ #include <iostream> #include <cstdlib> #include <stdio.h> #include <stdlib.h> #include <sstream> #include <string> #include <regex> using namespace std; extern int yylineno; extern int yylex(); void yyerror(char *s, ...); %} %error-verbose %union { int i; char *s; } %token<i> INT_NUM; %token<s> ORDER_BY_DESC; %% order_by: | ORDER_BY_DESC { string s($<s>1); string str = s.substr(0, s.size() - 1); char *x = new char[str.length() + 1]; order_by_stmt = str; strcpy(x, str.c_str()); $<s>$ = x; } ; %% void yyerror(char *s, ...) { va_list ap; va_start(ap, s); fprintf(stderr, "%d: error: ", yylineno); vfprintf(stderr, s, ap); fprintf(stderr, "\n"); } int main() { yyparse(); return 0; }

I have a line with ORDER BY DESC(?year) where ?year can be anything followed by a question mark (?) such as ?name, ?address etc. I have tried ORDER BY DESC$\?[a-z]+$ to capture the whole string as ORDER BY DESC(?year) but not working.

lex file:

%{ #include <cstdio> #include <iostream> #include "grammar.tab.h" %} %option case-insensitive %% [1-9][0-9]* { yylval.i = atoi(yytext); return INT_NUM; } "ORDER BY DESC$\?[a-z]+$" { yylval.s = strdup(yytext); return ORDER_BY_DESC; } "\n" { yylineno++; } \. { return DOT; } [ \t]+ { /* ignore white space */ } "#".* { /* ignore comments */ } [ \t\v\f\r]+ { } . { std::cerr << "Lexical Error!\n"; } %% int yywrap() { return 1; }

bison file:

%{ #include <iostream> #include <cstdlib> #include <stdio.h> #include <stdlib.h> #include <sstream> #include <string> #include <regex> using namespace std; extern int yylineno; extern int yylex(); void yyerror(char *s, ...); %} %error-verbose %union { int i; char *s; } %token<i> INT_NUM; %token<s> ORDER_BY_DESC; %% order_by: | ORDER_BY_DESC { string s($<s>1); string str = s.substr(0, s.size() - 1); char *x = new char[str.length() + 1]; order_by_stmt = str; strcpy(x, str.c_str()); $<s>$ = x; } ; %% void yyerror(char *s, ...) { va_list ap; va_start(ap, s); fprintf(stderr, "%d: error: ", yylineno); vfprintf(stderr, s, ap); fprintf(stderr, "\n"); } int main() { yyparse(); return 0; }